The application of hydrophilic coatings on medical devices has become a very important method to improve biocompatibility between living tissue and the medical device. Another important property of hydrophilic coatings is to reduce the friction and to render biomedical devices slippery when wet. Medical devices like catheters, guide wires, endoscopes etc. are often sliding in direct contact with the surface of living tissue when in use. Catheters and guide wires may e.g. be introduced into the blood vessels or a catheter for catheterization of the bladder is introduced through the urethra and withdrawn later after emptying the bladder when performing catheterization or after some time when performing more or less permanent catheterization. In both applications, the medical device is sliding in direct contact with a physiological surface, the walls of the blood vessels, or the mucosa of the urethra, respectively.
There is a need for improved, in particular simplified, methods for the preparation of medical devices.